Figures
Abstract
Background
We systematically reviewed observational studies of early mortality post-antiretroviral therapy (ART) initiation in low- and middle-income countries (LMIC) in Asia, Africa, and Central and South America, as defined by the World Bank, to summarize what is known.
Methods and Findings
Studies published in English between January 1996 and December 2010 were searched in Medline and EMBASE. Three independent reviewers examined studies of mortality within one year post-ART. An article was included if the study was conducted in a LMIC, participants were initiating ART in a non-clinical trial setting and were ≥15 years. Fifty studies were included; 38 (76%) from sub-Saharan Africa (SSA), 5 (10%) from Asia, 2 (4%) from the Americas, and 5 (10%) were multi-regional. Median follow-up time and pre-ART CD4 cell count ranged from 3–55 months and 11–192 cells/mm3, respectively. Loss-to-follow-up, reported in 40 (80%) studies, ranged from 0.3%–27%. Overall, SSA had the highest pooled 12-month mortality probability of 0.17 (95% CI 0.11–0.24) versus 0.11 (95% CI 0.10–0.13) for Asia, and 0.07 (95% CI 0.007–0.20) for the Americas. Of 14 (28%) studies reporting cause-specific mortality, tuberculosis (TB) (5%–44%), wasting (5%–53%), advanced HIV (20%–37%), and chronic diarrhea (10%–25%) were most common. Independent factors associated with early mortality in 30 (60%) studies included: low baseline CD4 cell count, male sex, advanced World Health Organization clinical stage, low body mass index, anemia, age greater than 40 years, and pre-ART quantitative HIV RNA.
Conclusions
Significant heterogeneity in outcomes and in methods of reporting outcomes exist among published studies evaluating mortality in the first year after ART initiation in LMIC. Early mortality rates are highest in SSA, and opportunistic illnesses such as TB and wasting syndrome are the most common reported causes of death. Strategies addressing modifiable risk factors associated with early death are urgently needed.
Citation: Gupta A, Nadkarni G, Yang W-T, Chandrasekhar A, Gupte N, Bisson GP, et al. (2011) Early Mortality in Adults Initiating Antiretroviral Therapy (ART) in Low- and Middle-Income Countries (LMIC): A Systematic Review and Meta-Analysis. PLoS ONE 6(12): e28691. https://doi.org/10.1371/journal.pone.0028691
Editor: Chiyu Zhang, Jiangsu University, China
Received: June 29, 2011; Accepted: November 14, 2011; Published: December 29, 2011
Copyright: © 2011 Gupta et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Funding for this project was provided by National Institutes of Health Grant R01 AI080417 awarded to Dr. Gupta. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Introduction
Ninety-five percent of the estimated 33.4 million HIV-infected adults live in low- and middle-income countries (LMIC) and approximately 7.1 million of these individuals have advanced HIV and are in need of antiretroviral treatment (ART) [1]. A massive global effort to provide ART is underway and if current trends continue, by 2015, 8 million HIV-infected persons will be receiving ART. ART has dramatically reduced morbidity and mortality worldwide [2]–[4]; however a >3-fold increased rate of mortality within the first 12 months post-ART initiation has been observed in LMIC compared to high-income countries [5].
A summary of cohorts of sub-Saharan African (SSA) settings previously identified a mortality estimate of 8%–26% at 12 months post-ART initiation [6]. However, this review did not include studies from Asia or the Americas, where substantial numbers of patients are also initiating ART. Furthermore, while it is clear that starting ART at higher CD4 counts will reduce mortality, many patients at ART clinics in LMIC continue to present with advanced HIV. Therefore, the objective of our study was to systematically review observational cohort data on early mortality, which we defined as death within 12 months post-ART initiation among persons in LMIC. We specifically wanted to measure the early mortality post-ART initiation in different regions, assess the relative causes of early mortality, and determine risk factors for mortality in these settings; such data are needed to inform global programs and global priorities for HIV care and treatment.
Methods
Search strategy and selection criteria
We searched Medline and EMBASE databases for articles published between January 1996, (when combination ART was heralded) and December 2010. Keywords used for the search strategy included “developing countries”, “Africa”, “South America”, “Asia”, “developing country”, “mortality”, “death”, “deaths”, “antiretroviral therapy”, “highly active”, “haart”, “anti-retrovirals”, “antiretrovirals”, “antiretroviral”, ”anti retroviral”, “highly active antiretroviral therapy” (see table S1 for exact search strategy used). We limited the search to human studies and articles published in English. A total of 1776 potentially relevant citations were identified and compiled from both electronic databases; 875 articles remained after elimination of duplicates. Three reviewers (NG, GN, AC) screened titles and abstracts to capture potentially relevant studies and one reviewer (AG) resolved any discrepancies between them. Studies were included if they met the following criteria: a) study was in a LMIC as defined by the World Bank in 2008 {http://data.worldbank.org/about/country-classifications}, b) age of the participants was ≥15 years, c) participants were ART naïve at baseline or the authors gave data separately for naïve and non-naïve, d) mortality was reported within the first year after ART initiation and, e) size of the cohort was >50 participants. We excluded editorials, case reports, abstracts, letters, reviews, clinical trials, studies including only children and studies that focused on deaths due to a specific opportunistic infection. Full text review was completed by three independent reviewers (GN, WY and NG). Additional data were not obtained from study authors.
Data extraction and analysis
For studies that met the inclusion criteria, data were extracted and results tabulated. The primary objective of the study was to measure early mortality post-ART initiation in different LMIC regions. The defined regions were LMIC in SSA, Asia, the Americas (South America, Central America and the Caribbean), and multi-regional (Africa, Asia and the Americas). We reported mortality data using the methods presented in each article including probability of survival using Kaplan-Meier curves; incidence rates; and proportions. Meta-analysis was done to estimate an overall and also a combined estimate of mortality rate within each region. Heterogeneity between the studies was examined using Cochran's Q and the I2 statistic [7]. The first step in getting the combined mortality rate was done by obtaining the number of deaths in individual studies. Most studies, that used Kaplan-Meier methods, summarized the number of deaths and the number in the risk set at each time point. For the few studies for which we did not have these data available, methods described in Parmar et al [8] and Whitehead & Whitehead [9] were used to estimate the number of deaths and lost to follow-up. If there was an evidence of variation between the studies, a random effects model was used to estimate the combined mortality rate and corresponding 95% confidence interval using standard methods [10], otherwise a fixed-effects model was used. The meta-analysis was summarized graphically using a Forest Plot. An analysis of publication bias was also performed using a Funnel Plot and Kendall's test [11]. All analyses were done using S-plus 8.1 (TIBCO, Palo Alto, CA) and StatsDirect (UK). A sensitivity analysis was done to estimate the bounds for the combined mortality rate. All lost-to-follow-up, for the upper bound were assumed to be dead (worst case scenario), and were assumed to be living for the lower bound (best case scenario). A DerSimonian & Liard estimate of mortality probability and corresponding 95% CI were calculated [10].
Our secondary outcomes of interest included reported causes of mortality and reported independent risk factors associated with early mortality in multivariate analysis. We reported these risk factor associations as hazard ratios or odds ratios as appropriate. Lastly, we assessed the quality of studies by evaluating the chance of ascertainment bias, which was calculated from two parameters: loss-to-follow-up reported and method for ascertainment of mortality reported. One point each was assigned for the above two parameters. Thus, the scoring was such that: 2 points indicated a low chance of ascertainment bias, 1 point indicated moderate chance of ascertainment bias and 0 points indicated high chance of ascertainment bias. We also assessed reporting of HIV-RNA plasma concentration, use of prophylaxis for opportunistic infections, adherence, control of confounding factors, and accounting for loss-to-follow-up. Confounder control in the included studies was considered to be adequate if multivariate analysis was performed (e.g., Cox proportional hazards or logistic regression to identify independent risk factors).
Results
Of 875 articles, 187 studies received full text review, of which 50 met our inclusion criteria {figure 1}. Of 50 included studies, 38 (76%) were from SSA, five (10%) were multi-regional (Africa, Asia, South and Central America and the Caribbean), five (10%) were from Asia and two (4%) were from the Americas (South and Central Americas and the Caribbean) {table 1}. Most studies (n = 47) were published between the years 2005–2010, with the largest number of publications being in 2008 (n = 17).
Flow chart constructed using the PRISMA guidelines (Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLoS Med 6(6): e1000097. doi:10.1371/journal.pmed1000097).
Base-line characteristics
The majority (48%) of studies were in an urban setting, 18% were in rural, 24% were in a mixed setting and 10% were unknown {table S2}. Cohort size ranged from 109–81,821 persons. The proportion of females ranged from 2%–81%. Thirty-four (68%) studies reported a median baseline CD4 cell count that ranged from 11–192 cells/mm3; median CD4 cell count was lowest from the Asian studies (11–41 cells/mm3). Fourteen (28%) studies reported median baseline log HIV-RNA concentrations that ranged from 4.6–5.7 log copies/ml. Median follow-up was reported by 42 (84%) studies and ranged from 3–55 months. Forty (80%) studies reported loss-to-follow-up, which overall ranged from 0.3%–27%. Lost-to-follow-up was highest in SSA.
Mortality characteristics
Mortality at the end of follow-up varied by region and ranged from 2.6%–29.7%, with the lowest reported from the South American cohort of a multi-regional study and highest from SSA. Forty (80%) studies reported on 12 month post-ART initiation mortality however method of mortality reporting varied {table 1}. The overall pooled estimate of mortality at 12-months post-ART initiation was 0.14 (95% CI 0.10–0.20) but varied substantially by region. The highest mortality estimate was in SSA 0.17 (95% CI 0.11–0.24) followed by Asia 0.11 (95% CI 0.10–0.13); the Americas 0.07 (0.007–0.20); and multiregional 0.08 (95% CI 0.06–0.10) {figure 2}. A sensitivity analysis to assess the best case scenario where all loss-to-follow-up were assumed to have survived versus the worst case scenario where all loss-to-follow-up were assumed to have died is shown in figure 3. The majority of deaths were found to have occurred in the first three months after ART initiation {table S2}.
Pooled estimates are summary random effects estimates with 95% confidence intervals. Two studies were excluded as they did not provide appropriate data for pooling (Djomand [23] and Yu [24]). The summary pooled estimate is 0.14 (95% CI 0.10–0.20). Test for heterogeneity by region was as follows [7]: Sub-Saharan Africa Cochran Q = 7691, p-value<0.0001 and I2 = 99.84% (95% CI 99.8%–99.8%)- suggesting there is an evidence of heterogeneity among studies; Asia Cochran Q = 1.67; p = 0.20– suggesting non-heterogeneous studies (I2 cannot be estimated since only 2 studies); Americas Cochran Q = 51.54; p<0.0001 – suggesting there is evidence of heterogeneity (I2 cannot be estimated since only 2 studies) and Multiregional: Cochran Q = 90.7; p<0.0001 and I2 = 96.7% (95% CI 94.7%–98.7%) suggesting there is evidence of heterogeneity.
Baseline risk factors associated with early mortality
Thirty-one (62%) studies [SSA, n = 24; Asia, n = 2; Americas, n = 1; Multi-region, n = 4] assessed independent risk factors associated with early mortality {table 2}. We did not report one of the 31studies due to insufficient data (strength of association of independent risk factors in terms of hazard or odds ratios were not reported) [12]. Factors assessed and reported to have independent association were: low baseline CD4 cell count (n = 23); advanced World Health Organization (WHO) clinical stage (n = 20); low body mass index (BMI) (n = 11); male sex (n = 9); anemia (n = 8); age (n = 5); weight (n = 4); ART adherence (n = 3); cotrimoxazole use (n = 2); total lymphocyte count (n = 2); high HIV RNA (n = 1); adherence to visits (n = 1); calendar year (n = 1); any education (n = 1); renal function (n = 1); Kaposi's sarcoma (n = 1); hospital type (n = 1); ART regimen (n = 1); tuberculosis (TB) clinic on site (n = 1); platelet count (n = 1); and fluconazole use (n = 1) {table S3}. When using standardized definitions across studies as shown in table 2, pre-ART CD4 cell count <50 cells/mm3, male sex, WHO clinical stage 4, low BMI<18.5, hemoglobin <8 g/dL, age >40 years, and pre-ART HIV RNA>5 log copies/ml carried the greatest risks for early mortality.
Causes of mortality
Fourteen (28%) studies reported cause-specific mortality [SSA, n = 11; Asia, n = 1; Americas, n = 2] {table 3}. Most common causes of death reported were TB accounting for 5%–44% of deaths; advanced HIV 20%–37%; wasting 5%–53%; chronic diarrhea 10%–25%; Cryptococcal meningitis 3%–18%; and Kaposi's sarcoma 3%–12%. Five (36%) of 14 studies reported a specific method for ascertaining the cause of death, of which two used verbal autopsy along with patient records. Most of the studies reported the causes of deaths based on clinical diagnosis but not microbiological confirmation.
Quality of studies
Most studies (92%) had low-to-moderate risk of ascertainment bias. However, only a small proportion disclosed prophylaxis for opportunistic infection (24%), or mentioned adherence (38%) {table S4}. There was evidence of heterogeneity or reporting bias as assessed by a funnel plot (Kendall's tau was 0.4 with p-value = 0.0046) {figure 4}.
The funnel plot assesses the hypothesis that the relationship between probability of death and study size, measured by standard error, is independent. This was tested using a Kendall's tau, which was estimated to be 0.4 with p-value = 0.0046, suggesting there is evidence of asymmetry. Although the presence of publication bias is a common explanation to an asymmetric funnel plot, data presented here are observational data without any intervention so the funnel plot asymmetry could also be due to heterogeneity in the data [25].
Discussion
In our study, we carefully reviewed and summarized the magnitude of early deaths occurring within the first 12 months post-ART initiation in different LMIC regions. Such data are needed by healthcare providers, policy makers, program funders alike to determine resource allocation and to optimize care and treatment strategies for HIV in LMIC. More than three-quarters of our included studies were from SSA. While this appears to reiterate that SSA continues to bear a large portion of global HIV burden, it also points to the relative lack of published data on early mortality from LMIC outside of SSA.
An overall estimate of mortality 12 months post-ART initiation was 14% with the highest probability being reported from SSA at 17%, followed by Asia at 11%, and the Americas at 7%. These differences could represent differences in factors such incidence of opportunistic infections, nutrition levels, socioeconomic levels and disease stage of study participants. However, it is also likely that some of the difference may be due to varying differences in economic and health infrastructure across regions. Consistent with this, Lawn et al have demonstrated an inverse ecologic relationship between growth domestic product (GDP) per capita and mortality proportion for 21 cohorts assessed [13]. However the specific reasons for such differences between regions could not be specifically teased out in our systematic review based on the available reported data.
Among the studies that reported on deaths within the first year of ART initiation, we observed that most deaths occurred within the first 3 months of ART initiation. This reflects the advanced stage of HIV disease of many participants in whom ART was initiated and is evidenced by the finding that more than 50% of included studies reported a median baseline CD4 cell count at or below 150 cells/mm3 and that the vast majority of patients had advanced HIV disease stage as ascertained by WHO clinical staging. It is clear from several published studies that starting ART at a higher CD4 cell count will reduce morbidity and avert the high mortality rates seen among patients with advanced HIV disease [14], [15]. For this reason, there has been a call for more aggressive testing and treating of HIV-infected persons upon identification of their HIV status irrespective of their CD4 cell count or disease stage as several decision models suggest that this is an optimal strategy to reduce HIV-associated morbidity and mortality in LMIC [16]. However, the cost-effectiveness and implementation of such a strategy remain unknown. Other strategies to reduce early mortality are likely to include better screening, prevention and management of opportunistic infections such as TB, better pre-ART care, and retention of patients in HIV programs. However, where to best focus limited financial resources needs further evaluation. Irrespective of what strategies are adopted, late presenters to care (HIV-infected patients with CD4 cell counts less than 200 cells/mm3) will remain an ongoing reality. Therefore, understanding the risks of death and assessing strategies to deal with early mortality in this vulnerable population remain critical.
Only one-third of included studies reported causes of death and the majority of these were from SSA. TB and wasting appeared to be the most common causes of early mortality. It is unclear as to what proportion of wasting in patients could be attributed to TB or other opportunistic infections, but it is likely that TB has some substantial contribution as an autopsy study in South Africa identified TB as the most common cause of death in patients receiving ART [17]. Approaches to reducing TB burden as a contributor to early mortality are needed and will likely include scaling up of TB prevention among HIV- positive adults seeking to start ART, using novel rapid TB detection methods such as Cepheid Gene Xpert MTB, and assessing the role of pre-emptive TB therapy along with starting ART in those at highest risk of early mortality, such as those with very advanced HIV disease. The latter strategy is being assessed by the AIDS Clinical Trials Group 5274 REMEMBER trial (NCT 1380080).
Other independent risk factors for early mortality included older age and male sex. Interestingly, older age has been associated with later presentation, diagnostic delays, as well as with immune senescence and poorer CD4 immune reconstitution, which may in part explain the findings [18], [19].The observation that males were in general more likely to die early in the course of therapy than females may be because of discrepancies in healthcare seeking behavior between the sexes or poorer adherence in men or due to biological differences in ART response, but these differences need to be further examined as prior studies have found mixed evidence for sex differences in HIV disease progression, adherence and HIV treatment outcomes [20]–[22].
While several studies have alluded to the underlying association between early mortality and poor nutrition, few studies have directly assessed this association. Most studies that have reported on nutrition have used BMI, body weight or hemoglobin levels as proxy markers of nutrition. While these are frequently used correlates of nutrition, their utility is confounded by the existence of co-morbidities in patients with HIV that may influence the body weight, BMI or hemoglobin levels. For example, anemia can be due to non-nutritional causes such as anemia of chronic disease due to HIV infection and likely represents a large proportion of the patients who were defined as having anemia in the included studies. However, iron deficiency anemia or anemia due to other micronutrient deficiencies were not ascertained in any of the studies, therefore the role of malnutrition-induced anemia contributing to early mortality remains inadequately assessed.
Our study had a few limitations. Like any systematic review, there is the possibility of incomplete retrieval or abstraction of data; however, we used three independent reviewers to try and best address this. Furthermore, we did not obtain raw data from study investigators for pooled estimation of mortality; however, we used only those studies from which appropriate Kaplan-Meier data could be extracted using published methods. There was also substantial heterogeneity and/or reporting bias among the studies, so the pooled estimates have to be understood in that context. Despite this heterogeneity, we felt it was important to pool the existing data to estimate mortality probability at 12 months as these data provide a more robust estimate than any single study alone. Furthermore, we performed a sensitivity analysis to assess best and worst case scenarios for mortality estimates based on assumptions made for those who were loss-to-follow-up. In addition, we could not pool risk factors or the reported causes of death such as low CD4 cell count or TB, respectively, as there were insufficient data included in the published studies to perform this.
In conclusion, more studies are needed to report on factors that affect early mortality in LMICs outside of SSA- in particular, high burden regions like South and Southeast Asia and Latin America. Future studies also need to focus on rural populations, more specific nutritional assessment and improved ascertainment of causes of death. Lastly, assessments of interventions directed at late presenters with advanced HIV are needed, as even with novel approaches such as HIV test-and-treat strategies, there will likely continue to be HIV-infected patients who present with advanced disease and remain at high risk for early mortality despite ART initiation.
Supporting Information
Table S1.
Exact search terms. The final search strategy was the combination of search terms 1, 2 and 3.
https://doi.org/10.1371/journal.pone.0028691.s001
(DOC)
Table S2.
Characteristics and mortality data from all studies of patients initiating ART in low- and middle-income countries grouped by region and by method of death reporting. F = female; IQR = Inter quartile Range; CD4 cell count = cells/mm3; SD = Standard deviation; PY = Person Years; Two studies had a mix of active and passive follow-up among their clinics. However, studies defined lost to follow-up in various ways and used different methods for tracing participants. § = Two studies used passive reporting and 11 active tracing, latter of which included home visits/community visits (n = 9), phone calls (n = 4) and letters (n = 2); others did not specify; # = Multivariable analysis of risk factors of death performed.
https://doi.org/10.1371/journal.pone.0028691.s002
(DOCX)
Table S3.
Studies assessing independent risk factors for early mortality organized by measure of association and by region. Ωonly those measures of association reaching statistical significance in multivariate analysis are included; BMI = Body Mass Index. All BMI values are baseline and in kg/m2 unless mentioned otherwise; CD4 = CD4 cell count. All CD4 counts are baseline and in cells/mm3 unless mentioned otherwise; Clinical staging = World Health Organization (WHO) Clinical staging unless mentioned otherwise; Hb = Hemoglobin, Hemoglobin values are baseline and in gm/dL unless mentioned otherwise; Age is in years unless mentioned otherwise; Viral Load = HIV–1 RNA plasma concentration, Viral load is in log copies/ml unless mentioned otherwise; TLC = Total leukocyte count, TLC is cells/mL unless mentioned otherwise; CTX site = Cotrimoxazole treatment site; TB = Tuberculosis; KS = Kaposi's Sarcoma; ART = Anti-retroviral therapy; HAART = Highly active antiretroviral therapy; F = Female; M = Male.
https://doi.org/10.1371/journal.pone.0028691.s003
(DOCX)
Table S4.
Qualitative assessment of included studies. 1Ascertainment bias was calculated from two parameters, a) Loss to follow–up mentioned and b) Active method for ascertainment of mortality. If loss to follow–up was mentioned 1 point was assigned and if there was an active method for ascertainment of mortality then 1 point was assigned. The scoring system was thus: 2 points- Low chance of ascertainment bias; 1 point- Moderate chance of ascertainment bias; 0 points– High chance of ascertainment bias; 2Cotrimoxazole/Tuberculosis prophylaxis; 3Adherence was evaluated in various methods such as assigning a care taker for the patient, prescribing medication for a standard duration and asking the patients to come with the completed kit, counseling the patients and their care takers at the initiation of antiretroviral therapy about the importance of being adherent to medication;4Confounder control was said to be adequate if multivariable analysis was performed; 5Losses to follow–up was defined in various forms by each study and was accounted by different means such as making phone calls, home visits, attendance from patient registers etc; 6Adherence counseling was done to patients/patient guardian at the time of initiation of ART but adherence was never measured during the follow–up; 7211(3.8%) were lost to follow–up after 1stART visit while 880(16%) were lost to follow–up later on.
https://doi.org/10.1371/journal.pone.0028691.s004
(DOCX)
Author Contributions
Conceived and designed the experiments: AG. Analyzed the data: AG AC GN NGupte WY NGummadi. Wrote the paper: AG WY AC NGupte NGummadi GB MH.
References
- 1.
Joint United Nations Programme on HIV and AIDS (UNAIDS) (2007) Financial Resources Required to Achieve, Universal Access to HIV Prevention, Treatment Care and Support. Available: http://data.unaids.org/pub/Report/2007/JC1678_Fin_Res_Req_en.pdf.
- 2. Palella FJ Jr, Delaney KM, Moorman AC, Loveless MO, Fuhrer J, et al. (1998) Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection. HIV Outpatient Study Investigators. N Engl J Med 338: 853–860.
- 3. Severe P, Leger P, Charles M, Noel F, Bonhomme G, et al. (2005) Antiretroviral therapy in a thousand patients with AIDS in Haiti. N Engl J Med 353: 2325–2334.
- 4. Stringer JS, Zulu I, Levy J, Stringer EM, Mwango A, et al. (2006) Rapid scale-up of antiretroviral therapy at primary care sites in Zambia: feasibility and early outcomes. JAMA 296: 782–793.
- 5. Braitstein P, Brinkhof MW, Dabis F, Schechter M, Boulle A, et al. (2006) Mortality of HIV-1-infected patients in the first year of antiretroviral therapy: comparison between low-income and high-income countries. Lancet 367: 817–824.
- 6. Lawn SD, Harries AD, Anglaret X, Myer L, Wood R (2008) Early mortality among adults accessing antiretroviral treatment programmes in sub-Saharan Africa. AIDS 22: 1897–1908.
- 7. Higgins JP, Thompson SG (2002) Quantifying heterogeneity in a meta-analysis. Stat Med 21: 1539–1558.
- 8. Parmar MK, Torri V, Stewart L (1998) Extracting summary statistics to perform meta-analyses of the published literature for survival endpoints. Stat Med 17: 2815–2834.
- 9. Whitehead A, Whitehead J (1991) A general parametric approach to the meta-analysis of randomized clinical trials. Stat Med 10: 1665–1677.
- 10. DerSimonian R, Laird N (1986) Meta-analysis in clinical trials. Control Clin Trials 7: 177–188.
- 11. Begg CB, Mazumdar M (1994) Operating characteristics of a rank correlation test for Publication bias. Biometrics 50: 1088–1101.
- 12. Wester CW, Kim S, Bussmann H, Avalos A, Ndwapi N, et al. (2005) Initial response to highly active antiretroviral therapy in HIV-1C-infected adults in a public sector treatment program in Botswana. J Acquir Immune Defic Syndr 40: 336–343.
- 13. Lawn SD, Harries AD, Wood R (2010) Strategies to reduce early morbidity and mortality in adults receiving antiretroviral therapy in resource-limited settings. Curr Opin HIV AIDS 5: 18–26.
- 14. Kitahata MM, Gange SJ, Abraham AG, Merriman B, Saag MS, et al. (2009) Effect of early versus deferred antiretroviral therapy for HIV on survival. N Engl J Med 360: 1815–1826.
- 15. Sterne JA, May M, Costagliola D, de Wolf F, Phillips AN, et al. (2009) Timing of initiation of antiretroviral therapy in AIDS-free HIV-1-infected patients: a collaborative analysis of 18 HIV cohort studies. Lancet 373: 1352–1363.
- 16. Granich RM, Gilks CF, Dye C, De Cock KM, Williams BG (2009) Universal voluntary HIV testing with immediate antiretroviral therapy as a strategy for elimination of HIV transmission: a mathematical model. Lancet 373: 48–57.
- 17.
Wong EB, Omar T, Setlhako G, Osih R, Murdoch D, et al. (2010) Causes of Death in ART-treated Adults: a Post-Mortem Study from Johannesburg. XVIII International AIDS Conference. Vienna, Austria.
- 18. Blanco JR, Caro AM, Perez-Cachafeiro S, Gutierrez F, Iribarren JA, et al. (2010) HIV infection and aging. AIDS Rev 12: 218–230.
- 19. Deeks SG (2011) HIV infection, inflammation, immunosenescence, and aging. Annu Rev Med 62: 141–155.
- 20. Alibhai A, Kipp W, Saunders LD, Senthilselvan A, Kaler A, et al. (2010) Gender-related mortality for HIV-infected patients on highly active antiretroviral therapy (HAART) in rural Uganda. Int J Womens Health 2: 45–52.
- 21. Kumarasamy N, Venkatesh KK, Cecelia AJ, Devaleenol B, Saghayam S, et al. (2008) Gender-based differences in treatment and outcome among HIV patients in South India. J Womens Health 17: 1471–1475.
- 22. Nicastri E, Leone S, Angeletti C, Palmisano L, Sarmati L, et al. (2007) Sex issues in HIV-1-infected persons during highly active antiretroviral therapy: a systematic review. J Antimicrob Chemother 60: 724–732.
- 23. Djomand G, Roels T, Ellerbrock T, Hanson D, Diomande F, et al. (2003) Virologic and immunologic outcomes and programmatic challenges of an antiretroviral treatment pilot project in Abidjan, Cote d'Ivoire. AIDS 17: Suppl 3S5–15.
- 24. Yu JK, Bong CN, Chen SC, Dzimadzi R, Lu DY, et al. (2008) Outcomes in HIV-infected patients who develop tuberculosis after starting antiretroviral treatment in Malawi. Int J Tuberc Lung Dis 12: 692–694.
- 25. Sterne JA, Sutton AJ, Ioannidis JP, Terrin N, Jones DR, et al. (2011) Recommendations for examining and interpreting funnel plot asymmetry in meta-analyses of randomised controlled trials. BMJ 343: d4002.
- 26. Alemu AW, Sebastian MS (2010) Determinants of survival in adult HIV patients on antiretroviral therapy in Oromiyaa, Ethiopia. Glob Health Action 3:
- 27. Sanne IM, Westreich D, Macphail AP, Rubel D, Majuba P, et al. (2009) Long term outcomes of antiretroviral therapy in a large HIV/AIDS care clinic in urban South Africa: a prospective cohort study. J Int AIDS Soc 12: 38.
- 28. Abaasa AM, Todd J, Ekoru K, Kalyango JN, Levin J, et al. (2008) Good adherence to HAART and improved survival in a community HIV/AIDS treatment and care programme: the experience of The AIDS Support Organization (TASO), Kampala, Uganda. BMC Health Serv Res 8: 241.
- 29. Banda AC, Makombe SD, Jahn A, Tweya H, Chuka S, et al. (2008) Antiretroviral therapy in the Malawi defence force: access, treatment outcomes and impact on mortality. PLoS One 3: e1445.
- 30. Bisson GP, Nthobatsong R, Thakur R, Lesetedi G, Vinekar K, et al. (2008) The use of HAART is associated with decreased risk of death during initial treatment of cryptococcal meningitis in adults in Botswana. J Acquir Immune Defic Syndr 49: 227–229.
- 31. Boulle A, Bock P, Osler M, Cohen K, Channing L, et al. (2008) Antiretroviral therapy and early mortality in South Africa. Bull World Health Organ 86: 678–687.
- 32. Bussmann H, Wester CW, Ndwapi N, Grundmann N, Gaolathe T, et al. (2008) Five-year outcomes of initial patients treated in Botswana's National Antiretroviral Treatment Program. AIDS 22: 2303–2311.
- 33. Hoffmann CJ, Fielding KL, Charalambous S, Sulkowski MS, Innes C, et al. (2008) Antiretroviral therapy using zidovudine, lamivudine, and efavirenz in South Africa: tolerability and clinical events. AIDS 22: 67–74.
- 34. Johannessen A, Naman E, Ngowi BJ, Sandvik L, Matee MI, et al. (2008) Predictors of mortality in HIV-infected patients starting antiretroviral therapy in a rural hospital in Tanzania. BMC Infect Dis 8: 52.
- 35. Laurent C, Bourgeois A, Mpoudi-Ngole E, Ciaffi L, Kouanfack C, et al. (2008) Tolerability and effectiveness of first-line regimens combining nevirapine and lamivudine plus zidovudine or stavudine in Cameroon. AIDS Res Hum Retroviruses 24: 393–399.
- 36. MacPherson P, Moshabela M, Martinson N, Pronyk P (2009) Mortality and loss to follow-up among HAART initiators in rural South Africa. Trans R Soc Trop Med Hyg 103: 588–593.
- 37. Marazzi MC, Liotta G, Germano P, Guidotti G, Altan AD, et al. (2008) Excessive early mortality in the first year of treatment in HIV type 1-infected patients initiating antiretroviral therapy in resource-limited settings. AIDS Res Hum Retroviruses 24: 555–560.
- 38. Mulenga LB, Kruse G, Lakhi S, Cantrell RA, Reid SE, et al. (2008) Baseline renal insufficiency and risk of death among HIV-infected adults on antiretroviral therapy in Lusaka, Zambia. AIDS 22: 1821–1827.
- 39. Mzileni MO, Longo-Mbenza B, Chephe TJ (2008) Mortality and causes of death in HIV-positive patients receiving antiretroviral therapy at Tshepang Clinic in Doctor George Mukhari Hospital. Pol Arch Med Wewn 118: 548–554.
- 40. Toure S, Kouadio B, Seyler C, Traore M, Dakoury-Dogbo N, et al. (2008) Rapid scaling-up of antiretroviral therapy in 10 000 adults in Cote d'Ivoire: 2-year outcomes and determinants. AIDS 22: 873–882.
- 41. Karcher H, Omondi A, Odera J, Kunz A, Harms G (2007) Risk factors for treatment denial and loss to follow-up in an antiretroviral treatment cohort in Kenya. Trop Med Int Health 12: 687–694.
- 42. Makombe SD, Harries AD, Yu JK, Hochgesang M, Mhango E, et al. (2007) Outcomes of tuberculosis patients who start antiretroviral therapy under routine programme conditions in Malawi. Int J Tuberc Lung Dis 11: 412–416.
- 43. Makombe SD, Jahn A, Tweya H, Chuka S, Yu JK, et al. (2007) A national survey of the impact of rapid scale-up of antiretroviral therapy on health-care workers in Malawi: effects on human resources and survival. Bull World Health Organ 85: 851–857.
- 44. Bekker LG, Myer L, Orrell C, Lawn S, Wood R (2006) Rapid scale-up of a community-based HIV treatment service: programme performance over 3 consecutive years in Guguletu, South Africa. S Afr Med J 96: 315–320.
- 45. Etard JF, Ndiaye I, Thierry-Mieg M, Gueye NF, Gueye PM, et al. (2006) Mortality and causes of death in adults receiving highly active antiretroviral therapy in Senegal: a 7-year cohort study. AIDS 20: 1181–1189.
- 46. Ferradini L, Jeannin A, Pinoges L, Izopet J, Odhiambo D, et al. (2006) Scaling up of highly active antiretroviral therapy in a rural district of Malawi: an effectiveness assessment. Lancet 367: 1335–1342.
- 47. Lawn SD, Myer L, Bekker LG, Wood R (2006) CD4 cell count recovery among HIV-infected patients with very advanced immunodeficiency commencing antiretroviral treatment in sub-Saharan Africa. BMC Infect Dis 6: 59.
- 48. Zachariah R, Fitzgerald M, Massaquoi M, Pasulani O, Arnould L, et al. (2006) Risk factors for high early mortality in patients on antiretroviral treatment in a rural district of Malawi. AIDS 20: 2355–2360.
- 49. Bourgeois A, Laurent C, Mougnutou R, Nkoue N, Lactuock B, et al. (2005) Field assessment of generic antiretroviral drugs: a prospective cohort study in Cameroon. Antivir Ther 10: 335–341.
- 50. Coetzee D, Hildebrand K, Boulle A, Maartens G, Louis F, et al. (2004) Outcomes after two years of providing antiretroviral treatment in Khayelitsha, South Africa. AIDS 18: 887–895.
- 51. Weidle PJ, Malamba S, Mwebaze R, Sozi C, Rukundo G, et al. (2002) Assessment of a pilot antiretroviral drug therapy programme in Uganda: patients' response, survival, and drug resistance. Lancet 360: 34–40.
- 52. Ruan Y, Xing H, Wang X, Tang H, Wang Z, et al. (2010) Virologic outcomes of first-line HAART and associated factors among Chinese patients with HIV in three sentinel antiretroviral treatment sites. Trop Med Int Health 15: 1357–1363.
- 53. Chasombat S, McConnell MS, Siangphoe U, Yuktanont P, Jirawattanapisal T, et al. (2009) National expansion of antiretroviral treatment in Thailand, 2000–2007: program scale-up and patient outcomes. J Acquir Immune Defic Syndr 50: 506–512.
- 54. Morineau G, Vun MC, Barennes H, Wolf RC, Song N, et al. (2009) Survival and quality of life among HIV-positive people on antiretroviral therapy in Cambodia. AIDS Patient Care STDS 23: 669–677.
- 55. Ferradini L, Laureillard D, Prak N, Ngeth C, Fernandez M, et al. (2007) Positive outcomes of HAART at 24 months in HIV-infected patients in Cambodia. AIDS 21: 2293–2301.
- 56. Corey DM, Kim HW, Salazar R, Illescas R, Villena J, et al. (2007) Brief report: effectiveness of combination antiretroviral therapy on survival and opportunistic infections in a developing world setting: an observational cohort study. J Acquir Immune Defic Syndr 44: 451–455.
- 57. O'Brien DP, Venis S, Greig J, Shanks L, Ellman T, et al. (2010) Provision of antiretroviral treatment in conflict settings: the experience of Medecins Sans Frontieres. Confl Health 4: 12.
- 58. Tuboi SH, Schechter M, McGowan CC, Cesar C, Krolewiecki A, et al. (2009) Mortality during the first year of potent antiretroviral therapy in HIV-1-infected patients in 7 sites throughout Latin America and the Caribbean. J Acquir Immune Defic Syndr 51: 615–623.
- 59. Calmy A, Pinoges L, Szumilin E, Zachariah R, Ford N, et al. (2006) Generic fixed-dose combination antiretroviral treatment in resource-poor settings: multicentric observational cohort. AIDS 20: 1163–1169.
- 60. Rougemont M, Stoll BE, Elia N, Ngang P (2009) Antiretroviral treatment adherence and its determinants in Sub-Saharan Africa: a prospective study at Yaounde Central Hospital, Cameroon. AIDS Res Ther 6: 21.
- 61. De Beaudrap P, Etard JF, Ecochard R, Diouf A, Dieng AB, et al. (2008) Change over time of mortality predictors after HAART initiation in a Senegalese cohort. Eur J Epidemiol 23: 227–234.
- 62. Nakanjako D, Kiragga A, Ibrahim F, Castelnuovo B, Kamya MR, et al. (2008) Sub-optimal CD4 reconstitution despite viral suppression in an urban cohort on Antiretroviral Therapy (ART) in sub-Saharan Africa: Frequency and clinical significance. AIDS Res Ther 5: 23.
- 63. Lowrance D, Makombe S, Harries A, Yu J, Aberle-Grasse J, et al. (2007) Lower early mortality rates among patients receiving antiretroviral treatment at clinics offering cotrimoxazole prophylaxis in Malawi. J Acquir Immune Defic Syndr 46: 56–61.
- 64. Jerene D, Endale A, Hailu Y, Lindtjoorn B (2006) Predictors of early death in a cohort of Ethiopian patients treated with HAART. BMC Infect Dis 6: 136.
- 65. Libamba E, Makombe S, Mhango E, de Ascurra Teck O, Limbambala E, et al. (2006) Supervision, monitoring and evaluation of nationwide scale-up of antiretroviral therapy in Malawi. Bull World Health Organ 84: 320–326.
- 66. Madec Y, Laureillard D, Pinoges L, Fernandez M, Prak N, et al. (2007) Response to highly active antiretroviral therapy among severely immuno-compromised HIV-infected patients in Cambodia. AIDS 21: 351–359.
- 67. Brinkhof MW, Dabis F, Myer L, Bangsberg DR, Boulle A, et al. (2008) Early loss of HIV-infected patients on potent antiretroviral therapy programmes in lower-income countries. Bull World Health Organ 86: 559–567.
- 68. Palombi L, Marazzi MC, Guidotti G, Germano P, Buonomo E, et al. (2009) Incidence and predictors of death, retention, and switch to second-line regimens in antiretroviral-treated patients in sub-Saharan African sites with comprehensive monitoring availability. Clin Infect Dis 48: 115–122.